1. Field of the Invention
The invention relates in general to the field of bicycles and, in particular, to bicycles which are driven by oscillating pedals whose motion is converted into a unidirectional rotation of the drive wheel.
2. Background of the Invention
The conventional drive mechanisms for nearly all bicycles consists of a roller chain and sprocket transmission driven by a pair of rotary pedal cranks. While this design combines the advantages of simplicity and low friction to provide an inexpensive and relatively efficient design, such design does not provide a uniformly effective conversion of the substantially linear driving force exerted by the legs of the rider into drive torque. At the top and bottom of the pedal travel drive torque is minimal and reaches a maximum value only at the midpoint of downward travel of each pedal.
In order to overcome such a disadvantage and provide a more uniformly effective conversion, numerous designs have been proposed using a pair of oscillating pedals coupled to pedal levers pivotally suspended from a preselected point on the bicycle frame or the rear hub whose oscillatory motion is converted into a unidirectional motion of the drive wheel. Examples of such designs may be seen in U.S. Pat. Nos. 3,375,023, 3,954,282, 3,913,945 and 3,039,790.
The downward force of the pedals in such designs is transmitted generally by flexible tension members to a drive mechanism which converts the linear motion of such cables into the rotary motion of the rear wheel. While such designs do provide a more uniformly effective conversion of the driving force exerted by the rider than the rotary pedal crank driving mechanism, such designs fail to utilize the full driving force exertable by the rider. Such failure is due, for example, to an inadequate drive mechanism to translate the linear motion of the tension members into the rotary motion of the rear wheel and to an inadequate rewind mechanism for the tension members so that the tension members transmit all the force exerted upon it by the pedals to the drive mechanism and also return the pedals to the uppermost position in order to receive the full driving force of the rider. In addition, no provision is made for transverse stabilization of the pedals and pedal levers and for effectively varying the length of the pedal stroke to obtain maximum power under the particular riding condition. Finally, no provision is made for rotatably restraining the feet of the rider, for enabling foot actuation of various mechanisms of the bicycle or for allowing the rider to exert his full driving force on the pedals while still permitting the rider to easily adjust his body position and at the same time assuring the safety of the rider.
Accordingly, it is a general object of the present invention to provide an improved oscillating pedal bicycle.
It is another object of the present invention to provide an oscillating pedal bicycle which has an improved drive and rewind mechanism.
It is a further object of the present invention to provide an oscillating pedal bicycle which allows the stroke of pedal to be effectively varied.
It is another object of the present invention to provide an oscillating pedal bicycle which permits the driver to exert his full driving force to the pedal and still easily adjust his body position.
It is a further object of the present invention to provide an oscillating pedal bicycle which provides for transverse stabilization of the pedals and includes rotatable foot restraints and foot actuated lever control mechanisms.